Thessalonica, founded in 315 BCE, was the chief city of the Roman province of Macedonia (now part of Greece). It was a major port on the Thermic Bay on the northwest edge of the Aegean Sea, and the Via Egnatia, the major Roman road across the Balkan peninsula, ending at Philippi to the east. At Paul’s visit, perhaps up to 200,000 people lived in this thriving center of culture and trade.